The chemistry and metabolism of protein components of connective tissues are being investigated. One of the objectives of this program is to define the biochemical pathway of synthesis, secretion and assembly of the components of the elastic fiber and the control of these processes. Attempts are made to sequence the elastin c-DNA clone and to use the cloned DNA to study the levels of elastin m-RNA in various tissues producing elastin. A second major objective is to examine and define the physicochemical, immunologic and biosynthetic aspects of basement membranes in a variety of tissues. Monoclonal antibodies are being produced to study the interrelationship of the collagenous components in basement membranes and to investigate their tissue localization. A third objective deals with the use of somatic cell hybridization to map the chromsomes which contain the structural genes that direct the synthesis of interstitial Type I and basement membrane Type IV collagens. Finally, efforts are directed at investigating the metabolic behavior of glomeruli and of aortas isolated from normal and diabetic rats. A new approach which enhances the incorporation of isotopically labeled amino acids into glomerular basement membrane is being examined.